In my experience, arrivals from Africa almost always end up at a remote stand. However, I always arrive in the 21:00 to 23:00 range, and that may well be the reason.

Despite the arrival time, I have often wondered if there's an element of "send the African arrivals to the remote stand" to avoid doing it to other arrivals containing people who Emirates prefers not to annoy.

That's unlikely, but that's how it feels sometimes.